960 resultados para coastal ecosystems
Resumo:
Phytoplankton population (3.37-56.09 x 10 super(4) cells/1) and pigments (chil. a 1.10-26.8 mg/m super(3)) in the waters off Porbandar indicated wide variations. Higher cell counts and lower diversity of species were encountered in the nearshore waters as compared to the waters of the seaward side. The concentration of dissolved oxygen was correlated with the phytoplankton population and pigments. 71 species belonging to 28 genera of algae were recorded. Species of Nitzschia were dominant almost at all stations. Species of Chaetoceros were very common along the middle and western transects.
Resumo:
Problems in India regarding the management of various coastal saline soil and waterlogged environments are discussed in detail, considering in particular the potential application of mixed fish farming systems. Various operational and cost requirements of such systems are examined.
Resumo:
Bangladesh has no naturally occurring Artemia, and all the growing shrimp hatcheries of the country depend entirely on import of cysts from foreign countries. Following successful inoculation of Artemia and production of cysts for the first time in this country in a coastal saltpan (at Chanua, Banskhali) by the senior author (in 1989-90), a similar second attempt was made under this programme in a saltpan (1000 m super(2)) of Demoshia, Chakaria, Cox's Bazar, Bangladesh between January and April 1992. A total of 1639.9 g (dry weight) of cysts (i.e. 5.46 kg DW/ha/month) have been produced using the Red Jungle Brand, whereas the previous attempt obtained 517 g of cysts (i.e. 2.07 kg DW/ha/month) using the Great Salt Lake Brand.
Resumo:
Five specimens of sessile barnacle, Chelonibia testudinaria (Linnaeus) were collected, in February 1993, from the back of a green turtle, Chelonea mydas, which was going back to the sea after laying eggs on Sandspit beach (24 degree 49'N; 66 degree 56'E). Chelonibia testudinaria is widely distributed throughout tropical and temperate seas and has only been reported to be found attached to turtles (Newman and Ross, 1976). In spite of its wide distribution it has not been reported from Northern Arabian Sea bordering Pakistan. The only species of genus Chelonibia known to occur in coastal waters of Pakistan is C. patula (Ranzani) recently reported by Javed and Mustaquim (1992). A brief description of C. testudinaria based on the present material is given below. All the specimens are housed in the Centre of Excellence in Marine Biology.
Resumo:
The marine environment near Karachi, particularly the Baba channel, Chari Kundi channel and Manora channel have been found contaminated with industrial effluents discharged by Malir and Lyari rivers, since they carry a high concentration of toxic heavy metals viz. Pb, Zn, Cu and Mn emanating from the industrial area and are received and discharged by the Lyari river. Out of 60 seawater samples collected from the above mentioned areas, Pb was present in 55 samples and Zn in 58 samples. The concentration of Pb was between 0.04 and 59.2ppm and the concentration of Zn was between 0.05 and 1.9ppm. Similarly all the 60 sludge samples collected from Lyari outfall and its adjoining area have been found to contain Pb and Zn in alarmingly high concentratios, which for Pb was between 15.4 and 3209.9ppm while for Zn was between 87 and 111.3ppm. Cu and Mn were also found in all the above samples.
Resumo:
One male and one female of Zozymodes cavipes (Dana, 1852) have revently been collected from the rocky shores near Karachi; the species is widely distributed in the Indo-Pacific region. It is, however, being reported for the first time from the pakistani coast of the northern Arabian Sea and thus fills the gap in the known distribution of the species. The pakistani material is housed in the Marine Reference Collection Centre, University of Karachi. The specimens are briefly descibed below. Only restricted synonym is given.
Resumo:
This report deals with the application of knowledge of mangrove ecosystems from around the world to the understanding of the present status of mangroves ecosystems in Pakistan.
Resumo:
The internal structure of rain falls in terms of rain rate during various instances of time can be determined by measuring rain amounts received during very short intervals of time. A system that can record the intensity of rain fall at every minute has been used for this study.
Resumo:
Life cycle and population biology of a perennial halophyte Arthrocnemum indicum Willd, was studied from February 1992 to January 1993. During the 12 months, the population was exposed to great variations in soil salinity from 35 to 58 ms/cm2 and soil moisture ranging from flood to drought levels. Seasonal changes in dry weight are directly related to soil salinity stress. When salinity levels become low, the dry matter production increases. A little increase in dry weight from April to July indicates that more negative soil water potentials were limiting plant growth. Proline content increased considerably during the dry season with a corresponding increase in salinity. Water soluble oxalate did not vary much with changes in salinity.
Resumo:
With the stimulus of the very high international market value of penaeid shrimp, new pond areas for shrimp farming are rapidly being added in Bangladesh. Unfortunately, this expansion is occurring with the loss of some natural mangrove forests and with soils and sediments that are far from ideal for aquaculture. In this study, two representative shrimp farming areas were surveyed and pH, in profile depth, was recorded. It was found that the shrimp farming areas of the Chakaria Sundarban are more acidic than those of the Khulna-Satkhira region due to the acid sulfate soils.